Power analysis attacks are attacks in which the attacker monitors variations in the power consumption of a hardware device during its operation for extracting cryptographic keys and other secret information from the device. Differential Power Analysis (DPA) is a power analysis method that allows an attacker to extract secret information during the computation of cryptographic computations via statistical analysis of the power consumed over multiple cryptographic operations.
Power analysis attacks are typically non-invasive and therefore hard to detect. A general approach to protect against power analysis attacks such as DPA is to design the hardware so that power consumption variations do not reveal secret information.